BANGALORE DIABETES CENTRE

Diet for Calcium Oxalate Stones

Introduction

Urinary calculi or kidney stones may be formed in the kidney, ureter, bladder or urethra. They consist of an organic matrix with interspread crystals and vary in size from fine granual to large stones.

The majority of urinary calculi are made up of calcium phosphate, calcium oxalate, uric acid or magnesium ammonium phosphate. In India, the most common type of calculi is calcium oxalate.

Calcium oxalate stones are formed when the urine becomes oversaturated with oxalate while the amount of intestinal calcium is limited. When your fluid intake decreases and your intake of oxalate increases, the oxalate sediment starts to build up in your kidneys, predisposing you to stone formation, according to "Williams Textbook of Endocrinology."

Kidney stones removed from patient's bod

RECOMMENDED DIETARY ALLOWANCES OF CALCIUM FOR INDIANS

Age Group

RDA of Calcium (mg/day)

Man

Sedentary work

Moderate work

Heavy Work

Woman

Sedentary Work

Moderate Work

Heavy Work

Pregnant Woman

Lactation

0-6 Months

6-12 Months

Infants

0 -6 Months

6-12 Months

Children

1-3 Years

4-6 Years

7-9Years

Boys

10-12 Years

13-15 Years

16-18 Years

Girls

10-12 Years

13-15 years

16-18 Years

400

400

400

400

400

400

1000

1000

1000

500

500

400

400

400

600

600

500

600

600

500

Sypmtoms of kidney stones:

Pain usually begins in mid or lower back and spreads to your abdomen as the stone moves toward your bladder. Some of the symtoms incude:

Severe pain

Blood in urine

Cloudy or smelly urine

Burning feeling while you urinate

Fever

Chills

Nausea and vomitting

ETIOLOGY:

Heredity

Infection of urinary tract

Hot climate

Lack of fluids

Excessive intake of calcium and vitamin D

Primary Hyperparathyroidism

Congenital malformation

Vitamin A and B Complex deficiency

FLUIDS

In all cases, patients need more fluid after exertion and during times of stress. If they drink enough, the urine should be pale and almost watery, not dark and yellow.

Fluids and side effects:

Lemon juice: Drinking one cup of lemon juice everyday increases citrate levels in the urine which helps to protect against calcium stones.

Grapefruit juice: Studies have found a risk for stones from drinking grapefruit juice.

Soft drinks should be avoided. Beer and other alcoholic beverages contain purines which may increase the less common uric acid stones.

Water:

Although water is best, it may vary depending on its source. Variations in water itself may have different impacts. Water hardness (meaning how much calcium is in the water) generally plays only a small role in stone formation. By far, the amount of fluid intake is most important in preventing stones.

How do fluids help?

Types of fluids which can be used

Types of fluids to be avoided

How much to drink?

Drinking fluids helps in preventing all types of kidney stones.

Water is the best option

Black tea is not recommended for people who have a tendency to get kidney stones as it contains high amount of oxalates.

Depends mainly on the weather and the person’s activity level

Drinking enough fluids help in keeping the urine diluted and in flushing out the stone forming minerals from the body.

Some studies recommend citrus fruit juices. They may help in preventing calcium oxalate and uric acid stones but may be harmful for people with calcium phosphate stones.

Grapefruit juice, cranberry juice and dark colas should be avoided by people who are prone to develop calcium oxalate kidney stones.

People living in tropical countries need to drink more water. Approximately two and a half to three litres of fluid are required for people living in tropics in summer.

Moderate intake of beer and wine may protect against stone formation.

People with kidney stones should drink water and other liquids to produce at least two litres of urine each day.

DIET AND KIDNEY STONES

Diet is one of the factors which can influence kidney stone formation. Dietary restrictions of different types of nutrients have to be followed for different types of kidney stones.

Limit food high in oxalate. When these food items are consumed, excessive amounts of oxalates are excreted in urine, which combines with calcium to form calcium oxalate stones.

·Increasing the intake of calcium also helps in preventing calcium oxalate stones because calcium binds oxalate in the gut and prevent it from getting excreted through urine.

·Vitamin C and Vitamin D supplements also can increase the risk of getting renal stones. Vitamin C or ascorbate can be converted to oxalate in body.

·Reducing the salt intake will help in preventing calcium stones. Increased sodium in the urine can cause increased excretion of calcium in the urine; increased level of calcium can combine with oxalates and phosphates to form calcium stones. Reducing salt intake is preferred to reducing calcium intake.

·Calcium from food and supplements taken along with food will bind to oxalate in food. This compound does not enter the blood and urinary tract thereby preventing the formation of calcium oxalate kidney stones.

·Foods that contain high levels of sodium like hot dogs, canned soups and vegetables, processed frozen foods, luncheon meats and fast food should be limited.

The fruits that are the lowest in oxalate are bananas, plums, pineapple, cherries, grapefruit, white grapes, melons, pears, nectarines and mangoes.

Tender coconut water.

Barley water.

Plantain rhizome juice.

Bitter gourd.

Studies conducted at National Institute of Nutrition, Hyderabad (1985)showed that L-Tartaric acid, a component of tamarind is an inhibitor of urolithiasis and wheat based diets had properties which can be considered conducive to uric acid and calcium oxalate crystalluria.